Yeah, I had the little cupcakes on my ICs on the Zen amp, and played with them for a few minutes with the ZMA - no difference at all. I even got a nice steel bin to put them in to do the With/Without test (since the directions say you need a Faraday cage to "remove them from the room"). I hear no difference at all. Not even a little bit.

I'm trying to get a friend of mine to request the bigger cupcake sized ones just to give them a better chance (since they are free after all), but I'm not trying too hard.

Just seems like snake oil to me. I'll concentrate on diffusers and absorbers which actually do make a huge difference for little money.

Well then ... looks like they aren't a hit around here. I'll check them out and report back if I here anything beneficial. Luckily they let you try before you buy, so that's at least one positive note about their company.

Looks like these are turning into a slippery situation with a few of you! I'm all for stuff if it works but I have to say I am a whole lot skeptical about these. Looking forward to reading about more attempts to see how these work if they do. These aren't cheap either unless of course if they worked.

What I think these are made of is ferrite, like the ferrite chokes I have put on some of my DIY power cords. They are supposed to reduce EMI and RFI. You put them near the connection point on cables to reduce what gets picked up by the cable over its run to the amp, etc.

So, if that is what they are (or some other similar material), they could have some impact to the degree that they reduce the noise.

I think I paid $4 for a couple of these ferrite chokes from parts express. Given that these are cupcake shaped, they are probably work 10X that

I got my BlackDiscus' the other day and I brought them into my listening area, placed them in the recommended spots on my components, etc. And ...

Well at first I thought maybe I could hear something, but overall it is extremely subtle if anything and I doubt I could pick them out in a blind listening test. But I can say that they did no harm either.

Anyways, I'm not the best person to notice these changes as I've noticed that even cables don't make a huge difference to me like they do with some guys here. So I'm going to pass, but I give props to Mad Scientist Audio for at least letting you try before you buy.